Simple Past vs. Present Perfect Tense

The present perfect tense is normally used when we are talking about past events together with their present results.

James can’t walk because he has broken his leg.

James broke his leg sometime in the past, but its effect is still present – he still can’t walk.

Somebody has let the cat in. (= The cat is still in.)

The simple past tenseis preferred when we identify the person or thing responsible for a present situation.

Compare:

John has broken another window.

Although the process of breaking the window took place in the past, its effect is still present – the window is still broken. That is why we use a present perfect tense in this sentence.

Who broke the window? (NOT Who has broken the window?)

Here the focus is on the person who performed the action. Therefore we use a simple past tense in this sentence.

More examples are given below:

Who killed that spider? (NOT Who has killed that spider?)

‘Why are you crying?’ ‘Dad hit me.’ (NOT Dad has hit me.)

Columbus discovered America. (NOT Columbus has discovered America.)

The simple past tense is also used to refer to a belief that has just been shown to be true or false.

It is bigger than I thought. (NOT It is bigger than I have thought.)

She is prettier than I expected. (NOT She is prettier than I have expected.)

But you promised to buy me a good camera! (NOT But you have promised to buy me a good camera!)

Difference between American and British English

In American English, the simple pastis often used to give news. The present perfect tense is also possible, but it is rarely used. In British English the present perfect tense is preferred in this case.

There was an explosion near the temple. (US)

There has been an explosion near the temple. (GB)

Police arrested more than 800 suspected drug traffickers in raids throughout the country. (US)

Police have arrested more than 800 suspected drug traffickers … (GB)

Honey, I lost my cellphone. (US)

Honey, I have lost my cellphone. (GB)

Recently, some British newspapers too have regularly started using the simple past tense for news announcements. This practice is probably aimed at saving space.

In American English, the simple past tense is commonly used with indefinite past-time adverbs like already, yet, ever and before. In British English, these adverbs are almost always used with the present perfect tense.